WITH consecutive_seats AS (
    SELECT 
        LINE_ID,
        SEAT_NO,
        LAG(SEAT_NO, 1) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS prev_seat,
        LAG(RSV_STATUS, 1) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS prev_status,
        LEAD(SEAT_NO, 1) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS next_seat,
        LEAD(RSV_STATUS, 1) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS next_status
    FROM 
        SEAT_RESERVE
    WHERE 
        RSV_STATUS = '0'
),
valid_seats AS (
    SELECT 
        LINE_ID,
        SEAT_NO AS SEAT_F,
        LEAD(SEAT_NO, 2) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS SEAT_T,
        ROW_NUMBER() OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS rn
    FROM 
        consecutive_seats
    WHERE 
        prev_seat = SEAT_NO - 1 AND 
        next_seat = SEAT_NO + 1 AND
        prev_status = '0' AND 
        next_status = '0'
)
SELECT 
    LINE_ID AS LINE,
    SEAT_F,
    SEAT_T
FROM 
    valid_seats
WHERE 
    rn = 1
ORDER BY 
    LINE_ID DESC,
    SEAT_F ASC;